Electric tool with trigger switch and lock-out arrangement

ABSTRACT

The disclosure describes a portable electric tool having an onoff trigger switch and a motor reversing switch. The actuators for the two switches are so interlocked as to prevent the tool from being reversed while the tool is running. The tool housing has a separate integral cavity adjacent to the moving parts of the tool, such as the motor, for containing wires or solid state control devices and positively protects said wires or devices against physical or mechanical damage from the motor or related parts.

[56] Referen'ces' Cited j United, States Patent Jacyno I [541 ELECTRICTOOL WITH TRIGGER SWITCH AND LOCK-OUT ARRANGEMENT,

[ 72] Inventor: A nthony Jacyno, Aurora, 111.

73 'Assignee: c.- w; Murphy. Industries, Inc., I Portable Electric ToolDivision,

Houston, Tex.

1969, abandoned.

[52] [1.8. CI. ..310/47, 200/1 V, 200/50 R, g I 200/50 C, 200/157 [51]int. Cl. ..ll02k 11/00 [58] Field of Search ..310/47, 50, 68 R;200/1'57,

. 200/1 V, 50R, 50 C UNITED STATES" PATENTS 2,807,732 9/1957Kurtovich..,...;..,....200/157X 3,462,623 8/1969 Batson m1.

1451 Nov..2 l,1972

2,876,369 ,Doerner... ..310/50 x 3/1959 3,588,411 6/1971 Milcoy.;.'...,,.200/l57 3,422,296 1/1969 Frank ..200/157 X 2,936,349 5/1960Johson. ..200/50 C 3,467,801 9/ 1969 Matthews ..200/1 V X 2,711,4616/1955 l-lappe.... ..200/157 3,373,301 3/1968 Black ..200/157 X I3,376,402 5/1968 Bednarski ..200/157 3,260,827 7/1966 Frenzel ..200/157Primary Examiner-J. D. Miller Assistant Examiner-Mark O. BuddAttbrney-l-lofgren, Wegner, Allen, Stellman & Mc-

Cord

[57 ABSTRACT 3,344,291 9/1967 Pratt 3 Claims, 8 Drawing igures W 42 j 0I! 132 1:: 144 I if? a 1/1 1;; 1.90 4' 3 231.15 126 134 1:1

- l ELECTRIC TOOL Wm! TRIGGER SWITCH AND LOCK-OUT ARRANGEMENTCROSS-REFERENCE FIELD OF THE INVENTION This invention relates toelectric power tools and especially to such tools having reversiblemotors and related moving parts.

SUMMARY OF THEINVENTION The. present invention provides a new and usefulelectric power tool having a housing which contains a motor for drivingthe power tool. In one aspect of the invention, the motor is areversible motor and is turned on and off by a trigger switch in ahandle. portion of the housing. A two-way reversing switch is providedwith an actuator which is movable from either a forward or reverseposition depending on the direction in which the motor is to drive. Thereversing switch actuator and the trigger switch actuator areinterlocked so that the reversing switch cannot be moved while thetrigger switch is on. v

In another aspect of the invention, the housing of the tool is providedwith an integral cavity means for protecting wires, solid state devices,and the like from physical or mechanical damage by the motor or themoving parts of the tool. v

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail a specific embodiment of the invention with the understandingthat the present disclosure is to be considered as an exemplification ofthe principles of the invention and is not intended to limit theinvention to the embodiment illustrated.

2 DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of anelectric tool, in thiscase a drill, with parts broken away and insection, showing a preferred form of the invention;

FIG. 2 is a cross-sectional view of the motor reversing switch andsupporting frame taken on the line 2-2 of FIG. 1 with parts broken away;

FIG. '3 is a cross-sectional view of the motor reversing switch taken onthe line 33 of FIG. 2;

FIG. 4 is a view similar to FIG. 2, only showing the relationship of thereversing switch to the trigger switch and as a view along the line 44of FIG. 3 with the housing removed;

FIG. 5 is a cross-sectional view taken along the line 5-5 of FIG. 3 ofthe frame for holding the reversing switch, only with the switchremoved;

FIG. 6 is a front view of the frame of FIG. 5; FIG. 7 is a wiringdiagram fora reversible tool incorporating the reversing switch andtrigger switch of FIG. 1; and

FIG. 8 is a modified form of tool housing incorporat- I ing theinvention and having parts broken away and in section.-

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to;FIG. 1, thereis illustrated a portable electric drill having a housing 10 with amotor 12 and drive system (not shown) mounted therein in usual manner. Achuck 16 on the outside of the housing 10 is driven by motor 12 throughthe gear drive system (not shown). A ventilating fan blade 18 issecured-to the motor shaft to pull air through vents20 and exhaust airfrom vents 22 during operation of the motor for the purpose of removingheat from the housinginterior.

Housing 10, as illustrated, is known as a split housing design althoughit could be a stacked housing design such as shown in FIG. 8, andincludes a handle portion -1 1 having a trigger switch device 24 mountedtherein in normal manner. A power cord 26 supplies power through theswitch device to the motor via appropriate wiring 28. In the splithousing design, the housing is split along a vertical plane to dividethe housing into two halves 15 and 17 which are secured together byscrews 19. In the usual manner, the motor, transmission and variousoperative parts are secured in the one half 17 of the housing with thetop half 15 being secured thereon to enclose the parts.

As shown, the central portion of the housing has a bottom wall 30 whichhas an intermediate wall or barrier member 34 spaced interiorlytherefrom to form a container or cavity 32 in the housing. The inside ofsaid cavity 32 is protected from the moving parts of the motor 12, fan18 and gear means by the barrier member 34 so thatany elements in thecavity 32 are protected from any physical or mechanical damage which mayresult from malfunctioning of the moving parts of the tool. The housing'10 and the intermediate wall 34are formed ofa cast metal, such asaluminum, or of plastic of the high impact type in common use today.Materials, such as polycarbonate, which have insulating qualities aswell as impact qualities, are typical of the type that may be used forthe housing 10. The cavity 32 which can be located at any positionwithin the central portion of the housing, not necessarily the bottomposition illustrated, may contain wires such as the wires 28 and/or asolid state electronic control device such as device 38 which can beused for the purpose of controlling the speed of the drill. The wires 28exit from the cavity 32 by appropriate openings 33 in the wall 34 of thecavity.

The trigger switch device 24 includes an actuator in the form of atrigger 50 slidably mounted in handle 11 of the housing 10 for operatingan on-off switch 52 for controlling the motor. Referring to FIGS. 1-6, areversing switch 54 is mounted in a frame 57 above the on-ofi switch 52.Switch 54 is of the type having a pivoted actuating element 55 which canbe moved between either of two lateral on positions. With element 55 inone of the lateral on" positions, the motor 12 drives in one direction,but the motor is reversed by movement of element 55 to the other lateralon position.

The switch 54 is provided with an accessible actuator 56 which islikewise mounted in the mounting frame 57. The actuator 56 has a handleportion 66, a body portion 66a and a bifurcated end portion'69. A'pin 58is fixed in the body portion and projects from bothsides thereof intopivoting relationship in undercut bores 60 in the support lugs 61 of theframe 57. The actuator 56 includes the projecting handle portion 66extending through opening 59 in frame 57 and through opening 63 in thehandle 11 of the housing 10. The mounting frame-57 is made of plasticand, as best seen in FIG. 2, 4 and 5, has a general U-shape with thesupport lugs 61 being spaced apart and projecting from the base 65 ofthe U into the area between the parallel sides of the U. The bores oropenings 60 in the lugs 61 are undercut to provide a restricted neck 67between the bore 60 and the outer walls of the lug whereupon the ends ofthe pin 58 snap past the restricted neck 67 and into the openings 60 sothat the pin 58 and the actuator 56 are freeto pivot about the axis ofthe pin. I a Tongs 54a on the switch 54 have'screws 73 passingtherethrough into the mounting holes 73a in the end portions of thesides of the frame 57 for securing the switch 54 in the frame 57 and forpositioning the switch actuating element 55 in the opening in thebifurcated end 69 of the actuator 56. With the bifurcated end 69 ofactuator 56 receiving element 55 of switch 54 between its branches, itbecomes possible to move the element 55 between its forward or reversepositions by pivoting-actuator 56 about the axis of pin 58 throughpressure on the exposed portion 66 in the required direction. The frame57 with the actuator 56 and switch 54 assembled therewith as a unit ispositioned in the handle 11 by pressing the frame 57 into the cavity 71in the inside of the housing so that the portion 66 of the actuatorprojects out through the opening 63 in the handle. Projections 71a inthe housing half 17 extending from the walls of the cavity 71 coact withthe undercut portion 57a in the top and bottom outer portions of thelegs of the U of the frame 57 for holding switch 54 and its actuatingframe 57 trapped in the housing cavity until the other half is assembledto completely secure the switch 54 and frame 57 in position. Y

Trigger 50 has a pair of upstanding blocking ears 62 (FIGS. 1 and 4) andactuator '56 has a pair of depending blocking lugs 64. As best seen inFIG. 4, when actuator 56 is moved to one of its two positions to setswitch 54- in either a forward or a reverse actuating position, lugs 64on actuators 56 are pivoted to one side or the other with respect to theposition of the line of movement of ears 62 on the switch 52 so thatwhen the trigger 50 is depressed into the on position, the ears 62,which move linearly with said trigger 50, will move into a blockinglocation relative to the lugs 64 whereby the actuator 56 can not be'moved until the trigger switch 50, 52 is released and the motor stopsrunning in the designated direction.

So long as switch 52 remains depressed, actuator 56 cannot be pivotedaway from the selected forward or reverse position and especially cannotbe accidentally pivoted to move switch 54 to its other direction ofrotation position and reverse the motor while running. An attempt topivot actuator 56 to the other direction of rotation position results inthe side surfaces of lugs 64 bearing against the side surface of ears 62thereby blocking the pivotal movement.

FIG. 7 illustrates a suitable wiring diagram for use in the deviceshowing control of the motor, armature and field by switches 52 and 54to provide a reversible power tool. A suitable solid state speed control38 is shown in phantom.

FIG. 8 illustrates another form of the invention in conjunction with astacked housing design. The housing 1 10 has a forward end portion 11 1,an intermediate barrel portion 112 and a handle portion 114. The endportion 111 contains the gear train (not shown) and supports the chuckmember 116 and is fastened to the end of the barrel portion 112 by meansof screws 118. The barrel portion 112 contains the motor 120 and fan 122and has the intermediate barrier member or wall 124 thereacross toprovide a cavity 126-therein for housing wires 128 or solid statedevices 130. The handle portion 114 has the front of the hand gripportion 114a removable therefrom by screw 131 with the whole handleportion 114 being secured to the barrel portion 1 12 by screws 132. I

The housing 110 can be made of various materials but in the illustratedform the end portion 1 1 1 is of cast metal such as aluminum with thebarrel portion 112 and handle portion 114, 114a being of the electricalinsulating and high impact plastic material mentioned with respect toFIG. 1.

In the handle portion is mounted a trigger switch 134 having an actuator136 and the upwardly extending blocking ears 138 connected to theactuator 136 for linear movement therewith. A frame 140, which is of thesame general U-shape as frame 57 of the form of invention shown in FIGS.1-6, is molded as an integral part of thehandle 114 and has side legs142 to which the reversing switch 144 is secured as by screws (notshown) in the same manner as with the modification of FIG. 1. An opening146 is molded in the handle 114 through which the actuating handle 148of the actuator 150 projects. The actuator 150 is pivoted in the openportion of the U-shaped frame by means of the pins 152 seated in theundercut openings 154 of the projections 156 from the integral frame140, once again in the same fashion as described with respect to theform of invention shown in. FIGS. 16. The actuator has a bifurcatedportion 158 which embraces the pivotal operating element 160 of thereversing switch 144.

A pair of depending lugs 162 projectdownwardly from the bifurcatedportion 158 of actuator 150 in a position to lie on either one side orthe other of the ears 138 on the trigger 136 so as to prevent actuationof the actuator 150 when the motor is running in either a forward or areverse direction of rotation. The operation and functioning of theactuator 150 for the reversing switch 144 with respect to the switch 134is the same as that described with respect to actuator 56, reversingswitch 54 and switch 24 and will not be repeated here.

I claim:

1. A portable electric power tool having a housing containing a motorportion and a handle portion, a tool holder rotatable in said housing,said handle portion being general y P ndicular to the axis of the toolholder and having an on-off switch for controlling the motor, a triggerfor operating said on-off switch, a frame member carried by saidhousing, a reversing switch mounted on said frame member and having amovable element for setting the motor for forward or reverse rotation, amovably mounted actuator carried by said frame'member and engageablewith said movable element of said reversing switch to move said movableelement and thereby reset said reversing switch, said actuator extendingfrom the handle on the side thereof opposite said tool holder, saidreversing switch being generally between said on-off switch and saidtrigger, and means on said actuator coacting with means on said on-offswitch to prevent actuation of said reversing switch while said triggeris in the on position, said actuator comprising first blocking meansexsecond blocking means on the trigger switch comprises a pair of carsupstanding from the top of the trigger switch, said ears lying in thepath of said lugs when the trigger switch is in the on position to blockmovement of said actuator.

2. The device of claim 1 wherein said trigger is slidably mounted andsaid actuator is pivotally mounted on said frame member about a verticalaxis above said trigger.

3. The device of claim 1, wherein said depending lugs are of propershape to unblock the trigger on move- .ment of the actuator to anunblocking position in either of the two on positions thereby permittinga movement of the trigger switch to on position, said ears on saidtrigger with the trigger switch in on position moving with the triggerto a position blocking movement of said actuator by engagement with theactuator lugs.

1. A portable electric power tool having a housing containing a motor portion and a handle portion, a tool holder rotatable in said housing, said handle portion being generally perpendicular to the axis of the tool holder and having an on-off switch for controlling the motor, a trigger for operating said on-off switch, a frame member carried by said housing, a reversing switch mounted on said frame member and having a movable element for setting the motor for forward or reverse rotation, a movably mounted actuator carried by said frame member and engageable with said movable element of said reversing switch to move said movable element and thereby reset said reversing switch, said actuator extending from the handle on the side thereof opposite said tool holder, said reversing switch being generally between said on-off switch and said trigger, and means on said actuator coacting with means on said on-off switch to prevent actuation of said reversing switch while said trigger is in the ''''on'''' position, said actuator comprising first blocking means extending toward said on-off switch, and second blocking means on said onoff switch extending toward and engaging with said first blocking means on said actuator for blocking said actuator against movement when the trigger is is in the ''''on '''' position thereby preventing reversing the direction of rotation of the motor, said second blocking means being in unblocking position with respect to the first blocking means when said on-off switch is in the '''' off'''' position, said first blocking means on said actuator comprising a pair of lugs depending from the bottom of the actuator and the second blocking means on the trigger switch comprises a pair of ears upstanding from the top of the trigger switch, said ears lying in the path of said lugs when the trigger switch is in the ''''on'''' position to block movement of said actuator.
 1. A portable electric power tool having a housing containing a motor portion and a handle portion, a tool holder rotatable in said housing, said handle portion being generally perpendicular to the axis of the tool holder and having an on-off switch for controlling the motor, a trigger for operating said on-off switch, a frame member carried by said housing, a reversing switch mounted on said frame member and having a movable element for setting the motor for forward or reverse rotation, a movably mounted actuator carried by said frame member and engageable with said movable element of said reversing switch to move said movable element and thereby reset said reversing switch, said actuator extending from the handle on the side thereof opposite said tool holder, said reversing switch being generally between said on-off switch and said trigger, and means on said actuator coacting with means on said on-off switch to prevent actuation of said reversing switch while said trigger is in the ''''on'''' position, said actuator comprising first blocking means extending toward said on-off switch, and second blocking means on said on-off switch extending toward and engaging with said first blocking means on said actuator for blocking said actuator against movement when the trigger is is in the ''''on '''' position thereby preventing reversing the direction of rotation of the motor, said second blocking means being in unblocking position with respect to the first blocking means when said on-off switch is in the '''' off'''' position, said first blocking means on said actuator comprising a pair of lugs depending from the bottom of the actuator and the second blocking means on the trigger switch comprises a pair of ears upstanding from the top of the trigger switch, said ears lying in the path of said lugs when the trigger switch is in the ''''on'''' position to block movement of said actuator.
 2. The device of claim 1 wherein said trigger is slidably mounted and said actuator is pivotally mounted on said frame member about a vertical axis above said trigger. 